fix(llmadapters): accept a Claude session listing with no background jobs

internal/llmadapters/subprocess.go

@@ -1817,12 +1817,30 @@ func parseClaudeBGActiveJobs(data []byte) (map[string]bool, error) {
 	}
 	activeJobs := map[string]bool{}
 	collectClaudeBGActiveJobs(jsonRoot, 0, activeJobs)
-	if len(activeJobs) == 0 && claudeBGJSONShapeNonEmpty(jsonRoot) {
+	if len(activeJobs) == 0 && claudeBGJSONShapeNonEmpty(jsonRoot) && !isClaudeSessionListing(jsonRoot) {
 		return nil, errors.New("unrecognized non-empty JSON shape")
 	}
 	return activeJobs, nil
 }
 
+// isClaudeSessionListing reports whether value is the session listing
+// `claude agents --json` prints: an array of session objects, each carrying a
+// sessionId. Only background sessions carry a job id, so a listing of
+// interactive sessions alone is a recognized shape with no active jobs.
+func isClaudeSessionListing(value any) bool {
+	sessions, ok := value.([]any)
+	if !ok || len(sessions) == 0 {
+		return false
+	}
+	for _, session := range sessions {
+		fields, ok := session.(map[string]any)
+		if !ok || claudeBGStateString(fields, "sessionId") == "" {
+			return false
+		}
+	}
+	return true
+}
+
 func collectClaudeBGActiveJobs(value any, depth int, activeJobs map[string]bool) {
 	if depth > claudeBGInspectMaxDepth {
 		return

internal/llmadapters/subprocess_test.go

@@ -622,6 +622,34 @@ func TestParseClaudeBGActiveJobs(t *testing.T) {
 		}
 	})
 
+	t.Run("accepts a session listing with only interactive sessions", func(t *testing.T) {
+		payload, err := os.ReadFile(filepath.Join("testdata", "claude_agents_interactive_only.json"))
+		if err != nil {
+			t.Fatalf("read fixture: %v", err)
+		}
+		activeJobs, err := parseClaudeBGActiveJobs(payload)
+		if err != nil {
+			t.Fatalf("parseClaudeBGActiveJobs: %v", err)
+		}
+		if len(activeJobs) != 0 {
+			t.Fatalf("activeJobs = %#v, want empty", activeJobs)
+		}
+	})
+
+	t.Run("collects background ids from a mixed session listing", func(t *testing.T) {
+		payload, err := os.ReadFile(filepath.Join("testdata", "claude_agents_mixed.json"))
+		if err != nil {
+			t.Fatalf("read fixture: %v", err)
+		}
+		activeJobs, err := parseClaudeBGActiveJobs(payload)
+		if err != nil {
+			t.Fatalf("parseClaudeBGActiveJobs: %v", err)
+		}
+		if len(activeJobs) != 1 || !activeJobs["de41e310"] {
+			t.Fatalf("activeJobs = %#v, want only de41e310", activeJobs)
+		}
+	})
+
 	t.Run("allows empty arrays", func(t *testing.T) {
 		activeJobs, err := parseClaudeBGActiveJobs([]byte(`[]`))
 		if err != nil {

internal/llmadapters/testdata/claude_agents_interactive_only.json

@@ -0,0 +1,20 @@
+[
+  {
+    "pid": 10240,
+    "cwd": "/home/dev/projects/service-a",
+    "kind": "interactive",
+    "startedAt": 1789704757845,
+    "sessionId": "0a119af3-fa96-44b8-b975-e69936e7d0e2",
+    "name": "service-a-3b",
+    "status": "idle"
+  },
+  {
+    "pid": 75433,
+    "cwd": "/home/dev/projects/service-b",
+    "kind": "interactive",
+    "startedAt": 1789732852316,
+    "sessionId": "ad2fba54-17c1-4fe0-af6b-1722fbf5a636",
+    "name": "service-b-9f",
+    "status": "busy"
+  }
+]

internal/llmadapters/testdata/claude_agents_mixed.json

@@ -0,0 +1,22 @@
+[
+  {
+    "pid": 10240,
+    "cwd": "/home/dev/projects/service-a",
+    "kind": "interactive",
+    "startedAt": 1789704757845,
+    "sessionId": "0a119af3-fa96-44b8-b975-e69936e7d0e2",
+    "name": "service-a-3b",
+    "status": "idle"
+  },
+  {
+    "pid": 7035,
+    "id": "de41e310",
+    "cwd": "/home/dev/.local/share/cr/runs/run-1/workbench/reviewers/reviewer-a/repo",
+    "kind": "background",
+    "startedAt": 1790101202780,
+    "sessionId": "de41e310-0409-418b-bc03-809db309cd71",
+    "name": "read cr prompt",
+    "status": "busy",
+    "state": "working"
+  }
+]